A high-temperature heat-insulating refractory material for kilns and its preparation method

Abstract

This invention belongs to the field of refractory materials technology, specifically disclosing a high-temperature insulating refractory material for kilns and its preparation method. The high-temperature insulating refractory material for kilns, by mass percentage, comprises: 45-70% aggregate, 10-35% powder, 5-15% silicon carbide micro powder, 1-10% α-alumina micro powder, 1-10% alumina sol, 1-5% modified chopped basalt fiber, and 0.1-0.5% water-reducing agent. The modified chopped basalt fiber is obtained by surface modification of chopped basalt fiber with an aminosilane coupling agent, followed by a condensation reaction with acetylphenylboronic acid. This invention proposes a high-temperature insulating refractory material for kilns and its preparation method, which, through modification design and raw material optimization, comprehensively improves the overall performance of the refractory material, giving it characteristics such as low thermal conductivity, high temperature resistance, corrosion resistance, and good thermal shock stability, thereby meeting the actual needs of industrial kilns in high-temperature industrial fields.

Description

Technical Field

[0001] This invention belongs to the field of refractory materials technology, and particularly relates to a high-temperature heat-insulating refractory material for kilns and its preparation method. Background Technology

[0002] Industrial kilns are major energy-consuming equipment in industrial production, consuming enormous amounts of energy annually. This is particularly true in the heat processing of metallurgical, building materials, ceramics, glass, chemical, and electromechanical enterprises, where industrial kiln energy consumption can account for 40-70% of total energy consumption. In the energy-saving process of industrial kilns, besides modifications to heat sources, sintering processes, combustion processes, and kiln structures, the quality of the refractory materials used in the kilns also has a decisive impact on the energy-saving effect.

[0003] Refractory materials refer to inorganic non-metallic materials with a refractoriness of not less than 1580℃. They are high-temperature structural materials used in the construction of thermal equipment and face the effects of high temperatures, mechanical stress, thermal stress, and erosion, scouring, and wear from high-temperature gases, melts, and solid media. However, traditional high-temperature insulating refractory materials have high thermal conductivity, making it difficult to achieve efficient insulation. This is mainly due to the lack of an effective thermal barrier mechanism in the material's internal microstructure, leading to rapid heat conduction in high-temperature environments. In addition, traditional refractory materials have poor mechanical properties and thermal shock stability, especially prone to cracking or spalling under high-temperature conditions, seriously affecting their service life and safety.

[0004] Therefore, developing a high-temperature insulating refractory material that can withstand mechanical stress, chemical corrosion, and thermal shock under high-temperature environments, while possessing excellent thermal insulation properties to reduce heat loss, is an important technological direction for reducing heat storage and heat dissipation losses in industrial kilns. Summary of the Invention

[0005] Based on the above-mentioned technical problems, this invention proposes a high-temperature heat-insulating refractory material for kilns and its preparation method. Through modification design and raw material optimization, the comprehensive performance of the refractory material is improved, giving it the characteristics of low thermal conductivity, high temperature resistance, corrosion resistance and good thermal shock stability, thereby meeting the actual needs of industrial kilns in high-temperature industrial fields.

[0006] The present invention proposes a high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 45-70% aggregate, 10-35% powder, 5-15% silicon carbide micro powder, 1-10% α-alumina micro powder, 1-10% alumina sol, 1-5% modified short-cut basalt fiber, and 0.1-0.5% water-reducing agent;

[0007] The modified chopped basalt fiber is obtained by surface modification of chopped basalt fiber with an aminosilane coupling agent, followed by a condensation reaction with acetylphenylboronic acid.

[0008] In this invention, chopped basalt fibers are surface-modified with an aminosilane coupling agent to obtain chopped basalt fibers with amino groups on their surface. These fibers can undergo a Schiff base condensation reaction with acetylphenylboronic acid, thereby grafting boric acid groups onto the surface of the chopped basalt fibers. This significantly improves the dispersibility and interfacial bonding of the chopped basalt fibers, thereby increasing the amount of chopped basalt fibers added to the refractory material and further enhancing its corrosion resistance and reducing thermal conductivity. On the other hand, in subsequent production processes, the boric acid grafted onto the surface of the chopped basalt fibers reacts in situ with α-alumina micropowder and alumina sol to generate aluminum borate whiskers. These whiskers have a high melting point, high strength, and low thermal conductivity, providing strong bonding between aggregates and powders. This ensures that the refractory material is lightweight, has low conductivity, and also possesses good overall high-temperature strength and thermal shock resistance. Furthermore, the small size of the in-situ generated aluminum borate whiskers is more beneficial for improving the corrosion resistance of the refractory material than that of pre-synthesized aluminum borate.

[0009] Preferably, the chopped basalt fibers have a length of 3-6 mm and a diameter of 8-14 μm; the aminosilane coupling agent is γ-aminopropyltriethoxysilane.

[0010] The structure of the modified short-cut basalt fiber in this invention is shown below: In the above-mentioned modified chopped basalt fibers, organic boric acid is grafted onto the surface of the chopped basalt fibers, which not only improves the dispersibility and interfacial bonding of the chopped basalt fibers, but also allows them to react in situ with α-alumina micro powder and alumina sol to generate aluminum borate whiskers. This enhances the thermal insulation performance of refractory materials, while also improving the overall mechanical properties and corrosion resistance of refractory materials.

[0011] Preferably, the aggregate comprises calcium hexaaluminate particles and fused white corundum particles, wherein the mass ratio of calcium hexaaluminate particles to fused white corundum particles is 100:30-40.

[0012] The particle size of the calcium hexaaluminate particles is 3-8 mm, and the particle size of the fused white corundum particles is 1-3 mm.

[0013] In this invention, calcium hexaaluminate particles with a particle size ≥1mm and fused white corundum particles are selected as aggregates, which can play a skeleton role in refractory materials and provide excellent high-temperature stability and refractory performance for refractory materials.

[0014] Preferably, the powder comprises calcium hexaaluminate fine powder and fused white corundum fine powder, wherein the mass ratio of calcium hexaaluminate fine powder to fused white corundum fine powder is 100:40-50;

[0015] The particle size of the calcium hexaaluminate fine powder is less than 0.088 mm, and the particle size of the fused white corundum fine powder is less than 0.088 mm.

[0016] In this invention, powder with a particle size of <0.088mm is selected as the matrix material, which can be combined with aggregates to improve the density of refractory materials and further enhance their high-temperature resistance and resistance to erosion and penetration.

[0017] Preferably, the chemical composition of the calcium hexaaluminate includes: CaO 8-9wt%, Al2O3≥90wt%; the chemical composition of the fused white corundum includes: Al2O3≥99wt%, Fe2O3≤0.1wt%, SiO2≤0.1wt%.

[0018] Preferably, the particle size of the silicon carbide micro powder is less than 0.088 mm;

[0019] The chemical composition of the silicon carbide micro powder includes: SiC ≥ 97wt%, SiO2 ≤ 0.4wt%.

[0020] Preferably, the particle size D50 of the α-alumina micro powder is 3-10 μm;

[0021] The α-alumina micro powder contains ≥99wt% Al2O3.

[0022] Preferably, the pH value of the aluminum sol is 4-7;

[0023] The Al2O3 content in the aluminosilicate is 10-30 wt%.

[0024] Preferably, the water-reducing agent is polyethylene glycol with sodium tartrate end-capping;

[0025] The sodium tartrate-terminated polyethylene glycol is obtained by condensing carboxyl-terminated polyethylene glycol with sodium tartrate.

[0026] The structure of the sodium tartrate-terminated polyethylene glycol in this invention is shown below:

[0027] In this invention, the water-reducing agent is polyethylene glycol with sodium tartrate end-capping. The grafting of sodium tartrate and polyethylene glycol reduces the viscosity of the slurry and improves its fluidity. It achieves efficient dispersion through a dual mechanism of steric hindrance and electrostatic repulsion, which enables the powder and aggregate to be better combined. The resulting refractory material has a denser microstructure, fewer pores, and significantly improved flexural strength and compressive strength.

[0028] This invention also proposes a method for preparing high-temperature heat-insulating refractory materials for kilns, comprising the following steps:

[0029] S1. After mixing the aggregate, powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, modified short-cut basalt fiber and water-reducing agent, add water to the resulting mixture and mix well. The water content is controlled at 3-6 wt% to obtain a wet mixture.

[0030] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it, and sinter the resulting green body to obtain the high-temperature heat-insulating refractory material for kilns.

[0031] The beneficial effects of this invention are:

[0032] (1) In this invention, the refractory material uses calcium hexaaluminate and fused white corundum as matrix materials, providing excellent high-temperature stability and refractory performance. On this basis, modified short-cut basalt fibers are synergistically optimized with α-alumina micro powder and alumina sol to generate aluminum borate whiskers through in-situ reaction, further enhancing thermal shock resistance and high-temperature strength. In addition, the refractory material has low thermal conductivity and good heat preservation performance as a working material for high-temperature kilns. Sodium tartrate-terminated polyethylene glycol is used as a water-reducing agent, which significantly improves the rheological properties and construction adaptability of the slurry.

[0033] (2) In this invention, the refractory material has the characteristics of high temperature mechanical strength, low thermal conductivity, good thermal shock resistance, strong erosion resistance and impermeability, which improves the problems of insufficient high temperature mechanical properties, poor erosion resistance and heat preservation effect of existing kiln refractory materials; in addition, the raw materials required by this invention are widely available and easy to obtain, and have no toxic components, which is environmentally friendly. Attached Figure Description

[0034] Figure 1 The infrared spectrum of the modified short-cut basalt fiber described in Example 1;

[0035] Figure 2 This is a scanning electron microscope image of the high-temperature heat-insulating refractory material for the kiln described in Example 1. Detailed Implementation

[0036] The present invention will now be described in detail through specific embodiments. However, these embodiments are clearly provided for illustrative purposes and are not intended to limit the scope of the present invention.

[0037] The particle size of calcium hexaaluminate granules is 3-8 mm, and the main chemical components include: CaO 8-9 wt%, Al2O3 ≥ 90 wt%.

[0038] The particle size of the fused white corundum particles is 1-3 mm, and the main chemical components include: Al2O3 ≥ 99 wt%, Fe2O3 ≤ 0.1 wt%, SiO2 ≤ 0.1 wt%.

[0039] The fine powder of calcium hexaaluminate has a particle size of less than 0.088 mm, and its main chemical components include: CaO 8-9 wt%, Al2O3 ≥ 90 wt%.

[0040] The particle size of fused white fused alumina is less than 0.088 mm, and its main chemical components include: Al2O3 ≥ 99 wt%, Fe2O3 ≤ 0.1 wt%, and SiO2 ≤ 0.1 wt%.

[0041] The silicon carbide micro powder has a particle size of less than 0.088 mm and a chemical composition including: SiC ≥ 97 wt%, SiO2 ≤ 0.4 wt%.

[0042] The particle size D50 of the α-alumina micro powder is 3-8 μm, and the Al2O3 content in the α-alumina micro powder is ≥99wt%; the pH value of the aluminum sol is 4-7, and the Al2O3 content in the aluminum sol is 10-30wt%; the length of the basalt fiber is 3-6 mm, and the diameter is 8-14 μm.

[0043] Example 1

[0044] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 40% calcium hexaaluminate granules, 15% fused white corundum granules, 14% fine calcium hexaaluminate powder, 6% fine fused white corundum powder, 9% silicon carbide micro powder, 7% α-alumina micro powder, 5.2% alumina sol, 3.5% modified short-cut basalt fiber, and 0.3% FS20 water-reducing agent;

[0045] The modified short-cut basalt fiber is synthesized by the following method:

[0046] Basalt fibers were added to acetone and heated under reflux for 12 hours, then the water was cleared and the mixture was dried. The resulting basalt fibers were added to a mixed solution of ethanol and water (mass ratio 30:1) containing γ-aminopropyltriethoxysilane, with a mass ratio of basalt fibers to γ-aminopropyltriethoxysilane of 1:0.1. The mixture was heated to 50°C and stirred for 3 hours, then filtered, washed with water, and dried. The basalt fibers with the aminosilane coupling agent surface modified were added to ethanol and dispersed evenly. Then, 3-acetylphenylboronic acid was added, with a mass ratio of basalt fibers to 3-acetylphenylboronic acid of 1:0.05. The mixture was heated to 70°C and stirred for 2 hours, then filtered, washed with water, and dried to obtain the modified chopped basalt fibers.

[0047] The infrared spectrum of the modified short-cut basalt fiber is shown below. Figure 1 As shown, in modified short-cut basalt fibers, at 3724 cm⁻¹ -1 The peak of the stretching vibration of OH is located at 3015 cm⁻¹. -1 and 2846cm -1 The peaks at 1597 cm⁻¹ represent the stretching vibration peak and the antisymmetric stretching peak of CH on the benzene ring, respectively. -1 The peak at 1370 cm⁻¹ represents the stretching vibration of C=N imine. -1 The characteristic peak of the BO bond is at 1296 cm⁻¹. -1The peak at this location is a characteristic peak of the Si-O bond.

[0048] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0049] S1. Mix the calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, modified short-cut basalt fiber and FS20 water-reducing agent according to the above mass percentages, then add water to the obtained mixture and mix well. The water content is controlled at 5wt% to obtain a wet mixture.

[0050] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0051] Scanning electron microscope (SEM) images of the high-temperature heat-insulating refractory materials used in the above-mentioned kilns are shown below. Figure 2 As shown.

[0052] Example 2

[0053] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 33% calcium hexaaluminate granules, 12% fused white corundum granules, 25% fine calcium hexaaluminate powder, 10% fine fused white corundum powder, 5% silicon carbide micro powder, 8.9% α-alumina micro powder, 1% alumina sol, 5% modified chopped basalt fiber, and 0.1% FS20 water-reducing agent;

[0054] The modified short-cut basalt fiber was synthesized by the method described in Example 1.

[0055] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0056] S1. Mix the calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, modified short-cut basalt fiber and FS20 water-reducing agent according to the above mass percentages, then add water to the obtained mixture and mix well. The water content is controlled at 5wt% to obtain a wet mixture.

[0057] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0058] Example 3

[0059] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 50% calcium hexaaluminate particles, 20% fused white corundum particles, 7% fine calcium hexaaluminate powder, 3% fine fused white corundum powder, 10% silicon carbide micro powder, 1% α-alumina micro powder, 7.5% alumina sol, 1% modified short-cut basalt fiber, and 0.5% sodium tripolyphosphate;

[0060] The modified short-cut basalt fiber was synthesized by the method described in Example 1.

[0061] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0062] S1. Mix the calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, modified short-cut basalt fiber and FS20 water-reducing agent according to the above mass percentages, then add water to the obtained mixture and mix well. The water content is controlled at 5wt% to obtain a wet mixture.

[0063] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0064] Example 4

[0065] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 40% calcium hexaaluminate granules, 15% fused white corundum granules, 14% fine calcium hexaaluminate powder, 6% fine fused white corundum powder, 9% silicon carbide micro powder, 7% α-alumina micro powder, 5.2% alumina sol, 3.5% modified short-cut basalt fiber, and 0.3% water-reducing agent;

[0066] The modified short-cut basalt fiber was synthesized using the method described in Example 1; the water-reducing agent was sodium tartrate-terminated polyethylene glycol, which was synthesized using the following method:

[0067] Polyethylene glycol (PEG-1000) and succinic anhydride were mixed at a mass ratio of 5:1, heated to 110°C, and stirred for 4 hours. After vacuuming, carboxyl-terminated polyethylene glycol was obtained. The carboxyl-terminated polyethylene glycol was then dispersed evenly in water, followed by the addition of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The mass ratio of carboxyl-terminated polyethylene glycol, EDC, and NHS was 1:0.3:0.2. After stirring for 1 hour, sodium tartrate was added. The mass ratio of carboxyl-terminated polyethylene glycol to sodium tartrate was 1:0.5. After stirring for 6 hours, the mixture was concentrated, washed with water, and dried to obtain sodium tartrate-terminated polyethylene glycol.

[0068] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0069] S1. Mix the calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, modified short-cut basalt fiber and water-reducing agent according to the above mass percentages, add water to the obtained mixture and mix well, with the water content controlled at 5wt%, to obtain a wet mixture.

[0070] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0071] Comparative Example 1

[0072] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 40% calcium hexaaluminate particles, 15% fused white corundum particles, 14% calcium hexaaluminate fine powder, 6% fused white corundum fine powder, 9% silicon carbide micro powder, 7% α-alumina micro powder, 5.2% alumina sol, 3.5% chopped basalt fiber, and 0.3% FS20 water-reducing agent.

[0073] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0074] S1. Mix the calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, chopped basalt fiber and FS20 water-reducing agent according to the above mass percentages, add water to the obtained mixture and mix well, with the water content controlled at 5wt%, to obtain a wet mixture.

[0075] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0076] Comparative Example 2

[0077] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 40% calcium hexaaluminate particles, 15% fused white corundum particles, 14% fine calcium hexaaluminate powder, 6% fine fused white corundum powder, 9% silicon carbide micro powder, 7% α-alumina micro powder, 5.2% alumina sol, 3.0% chopped basalt fiber, 0.5% boric acid, and 0.3% FS20 water-reducing agent.

[0078] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0079] S1. Mix the calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, chopped basalt fiber, boric acid and FS20 water-reducing agent according to the above mass percentages, then add water to the obtained mixture and mix well. The water content is controlled at 5wt% to obtain a wet mixture.

[0080] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0081] Comparative Example 3

[0082] A high-temperature heat-insulating refractory material for kilns, comprising, by weight percentage: 40% calcium hexaaluminate granules, 15% fused white corundum granules, 14% fine calcium hexaaluminate powder, 6% fine fused white corundum powder, 9% silicon carbide micro powder, 7% α-alumina micro powder, 5.2% alumina sol, 3.0% amino surfactant-modified short-cut basalt fibers, 0.5% boric acid, and 0.3% FS20 water-reducing agent;

[0083] The amino surfactant-modified short-cut basalt fibers were synthesized by the following method:

[0084] Basalt fibers were added to acetone and heated under reflux for 12 hours. The water was then cleared and the mixture was dried. The resulting basalt fibers were then added to a mixed solution of ethanol and water (mass ratio 30:1) containing γ-aminopropyltriethoxysilane, with a mass ratio of 1:0.1 between the basalt fibers and γ-aminopropyltriethoxysilane. The mixture was heated to 50°C and stirred for 3 hours. The mixture was then filtered, washed with water, and dried to obtain the amino surfactant-modified short-cut basalt fibers.

[0085] The preparation method of the above-mentioned high-temperature heat-insulating refractory material for kilns specifically includes the following steps:

[0086] S1. According to the above mass percentages, calcium hexaaluminate granules, fused white corundum granules, calcium hexaaluminate fine powder, fused white corundum fine powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, amino surfactant-modified short-cut basalt fiber, boric acid and FS20 water-reducing agent are mixed evenly, and then water is added to the obtained mixture and mixed evenly, with the water content controlled at 5wt%, to obtain a wet mixture.

[0087] S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it at 110°C for 24 hours, and sinter the resulting green body at 1350°C for 3 hours to obtain the high-temperature heat-insulating refractory material for kilns.

[0088] Experimental test:

[0089] The refractory materials obtained in the examples and comparative examples were tested respectively, and the results are shown in Table 1.

[0090] Flexural strength was tested according to GB / T3001-2007; compressive strength was tested according to GB / T5072-2008; firing line variation was tested according to GB / T5988-2007; thermal shock resistance was tested according to the thermal shock fatigue test proposed in "Research on Evaluation of Thermal Shock Fatigue Behavior of Refractory Materials", and the residual flexural strength retention rate after 10 cycles of thermal shock fatigue testing and air cooling was measured; thermal conductivity was tested according to GB / T36133-2018; alkali corrosion resistance was tested by immersing the refractory material in a 10% sodium hydroxide solution, curing it at 80℃ for 24 hours, rinsing it with distilled water and drying it, and comparing the mass loss rate of the samples before and after immersion. Specific results are shown in Table 1.

[0091]

[0092] As can be seen from the table above, the refractory material obtained in the examples is superior to that in the comparative examples in terms of various properties. It can be seen that the present invention, through the modification of short-cut basalt fibers, has the characteristics of high-temperature mechanical strength, low thermal conductivity, good thermal shock resistance, and strong resistance to erosion and permeation.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-temperature heat-insulating refractory material for kilns, characterized in that, By weight percentage, it includes: 45-70% aggregate, 10-35% powder, 5-15% silicon carbide micro powder, 1-10% α-alumina micro powder, 1-10% alumina sol, 1-5% modified chopped basalt fiber, and 0.1-0.5% water-reducing agent; The modified chopped basalt fiber is obtained by surface modification of chopped basalt fiber with an aminosilane coupling agent, followed by a condensation reaction with acetylphenylboronic acid.

2. The high-temperature heat-insulating refractory material for kilns according to claim 1, characterized in that, The chopped basalt fibers are 3-6 mm in length and 8-14 μm in diameter; the aminosilane coupling agent is γ-aminopropyltriethoxysilane.

3. The high-temperature heat-insulating refractory material for kilns according to claim 1, characterized in that, The aggregate includes calcium hexaaluminate particles and fused white fused alumina particles, with a mass ratio of calcium hexaaluminate particles to fused white fused alumina particles of 100:30-40. The particle size of the calcium hexaaluminate particles is 3-8 mm, and the particle size of the fused white corundum particles is 1-3 mm.

4. The high-temperature heat-insulating refractory material for kilns according to any one of claims 1-3, characterized in that, The powder includes fine calcium hexaaluminate powder and fine fused white corundum powder, with a mass ratio of 100:40-50 between the fine calcium hexaaluminate powder and the fine fused white corundum powder. The particle size of the calcium hexaaluminate fine powder is less than 0.088 mm, and the particle size of the fused white corundum fine powder is less than 0.088 mm.

5. The high-temperature heat-insulating refractory material for kilns according to claim 3, characterized in that, The chemical composition of the calcium hexaaluminate includes: CaO 8-9wt%, Al2O3≥90wt%; the chemical composition of the fused white corundum includes: Al2O3≥99wt%, Fe2O3≤0.1wt%, SiO2≤0.1wt%.

6. The high-temperature heat-insulating refractory material for kilns according to any one of claims 1-3, characterized in that, The particle size of the silicon carbide micro powder is less than 0.088 mm; The chemical composition of the silicon carbide micro powder includes: SiC ≥ 97wt%, SiO2 ≤ 0.4wt%.

7. The high-temperature heat-insulating refractory material for kilns according to any one of claims 1-3, characterized in that, The particle size D50 of the α-alumina micro powder is 3-10 μm; The α-alumina micro powder contains ≥99wt% Al2O3.

8. The high-temperature heat-insulating refractory material for kilns according to any one of claims 1-3, characterized in that, The pH value of the aluminum sol is 4-7; The Al2O3 content in the aluminosilicate is 10-30 wt%.

9. The high-temperature heat-insulating refractory material for kilns according to any one of claims 1-3, characterized in that, The water-reducing agent is polyethylene glycol with sodium tartrate end capping; The sodium tartrate-terminated polyethylene glycol is obtained by condensing carboxyl-terminated polyethylene glycol with sodium tartrate.

10. A method for preparing a high-temperature heat-insulating refractory material for kilns according to any one of claims 1-9, characterized in that, Includes the following steps: S1. After mixing the aggregate, powder, silicon carbide micro powder, α-alumina micro powder, alumina sol, modified short-cut basalt fiber and water-reducing agent, add water to the resulting mixture and mix well. The water content is controlled at 3-6 wt% to obtain a wet mixture. S2. Pour the wet mixture into a mold, cure it at room temperature, demold it, dry it, and sinter the resulting green body to obtain the high-temperature heat-insulating refractory material for kilns.

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